Means for and method of drop-forging crank shafts



March 11,1924, 1,486,587

H. H. KEEPORTS MEANS FOR AND METHOD OF DROP FORGING CRANK SHAFTS FiledMay 17, 1919 3 Sheets$heet l Qttmncq March 11 1924. 1,486,587 H. H.KEEPORTS I MEANS FOR AND METHOD OF DROP FORGING CRANK SHAFTS Filed May17, 1919 3 Sheets-Sheet 2 an uenfoz March 11 1924. 1,48%,587

H. H. KEEPORTS MEANS FOR AND METHOD OF DROP FORGING CRANK SHAFTS FiledMay 17 1919. 3 Sheets-Sheet 3 I fl -filmventoz flaw? fiffffpoero r 3&1,

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' HARRY H. EPORTS, OF DETROIT, MICHIGAN.

MS FOR AND .METHOD OF DROP-FORGING CRANK SHAFTS.

Application filed may 17, 1919. Serial Ito. 297 848.

To all whom it may concern.

Be it known that I, HARRY I-I. KEEPoRTs, -a citizen of the UnitedStates, residing at Detroit, in the county of Wayne and State e ofMichigamhave invented certain new and useful Improvements in Means forand Methods of Drop-Forging Crank Shafts, of which the following is aspecification.

This invention relates to improved means it or dies for dropforgingcrank shafts and tlfiefrpethod or process of forming the crank s a Theobjects of the invention are to pro- I vide improved methods of formingcrank shafts and whereby the structure of the metal will not be strainedby the twisting after forgin and to improve the process.

Objects which relate to mere details will appear from the description tofollow.

The objects of this invention are accomplished by the devices and meansdescribed in the following specification. The invention is defined andpointed out in the claims.

I A structure, which is a preferred embodi- 26 ment of the invention isclearly illustrated in the accompanying drawings forming a part of thisspecification, in which:'

Fig. I is a plan view of the dies for drop forging the crank shaft.

Fig. II is an elevation of the dies somew at separated looking againstthe lower si e of Fi I. I

Fig. III is a vertical detail sectional view of the dieswith a;completely forged crank shaft disposed therein, the same being taken ona line corresponding to line 33 of Figs. I, IV and VI, arts of the crankthrows being by dotted ines.

Fig. IV is a transverse detail sectional view taken on linecorresponding to line 4-4 of Fig. III, the position of art of the prankthrows being indicated by dotted mes.

Fig. V' is an enlarged fragmentary -detail view artially in section online 5-5 of Figs. II and VI, of the integral forming projection 3 of thebottom die.

' Fig. VI is a detail view of the operating faces of the bottom and topdies 1 and 2 placed side by side.

Fig. VII is an illustration of the billet from which the crank shaft isformed.

Fig. VIII is a plan view of the same after the first bending operationperformed by the die.

Fig. IX is an elevation View of the crank shaft after such preliminarybending operation.

Fig. X is a plan view of the crank shaft after the final operation ofthe forming dies before the fin or flash has been trimmed 0d.

Fi XI is a perspective view of the complete y formed crank shaft readyfor machining.

Fig. XII is an end elevation view of this complete crank shaft.

In the drawing, similar numerals of reference refer to similar partsthroughout the several views.

Considering the numbered parts of the drawing, the bottom die 1 isformed with double impressions, one at the edge for the preliminarybending of the crank shaft in a vertical plane in which are upwardprojections 3, 3 for deflecting portions of the shaft laterally at eachside of the center and with depressions 4, 4: for the centrally disposed throws of the crank shaft. orresponding depressions 5, 5 to therojections 3, 3 are in the upper die dispose at an angle and projections6, 6' are on the upper die corresponding to the depressions at, I in thelower die.

The projections 3, 3 are disposed at an angle to compensate or allow forthe bending of the blank in the second impression and their uppersurfaces are curved as indicated in Fig. V, the diagonal relationappearing in Fig. VI. This permits the bending of the 'metal withoutundue strain at these points and conforms the part at this preliminarybend so that it will be correctly and readily deflected when thepartially bent shaft is passed to the second die recess.

The second recess in the die is provided with deep end cavities 7, 7 inthe bottom die for receiving the end throws of the crank, as clearlyappears in Fig. III. Corresponding pro ections 8, '8' on the upper die 1coact therewith. Recesses 9, 9 are disposed laterally adjacent to theseend cavities as will be seen by referring to the dotted lines in Fig.III and the full lines in the dies 1 and 2 of Fig. VI. The precise angleof the same to the bottom cavity appears by the dotted lines in Fig. IV.The

central throws of the crank are formed by the laterally disposedrecesses 10, 10' on the opposite side, as will be seen by the transversesectional view shown in Fig. IV and the plan view in Fig. VI. Theserecesses coact with recesses 11, 11 and 12, 12 in the top dierespectively.

The straight billet 13 is first operated upon by the preliminary bendingas seen in Figs. VIII and IX on the first or edge recesses of the dies.The central crank throws 15, 15 are struck down into the cavities 4:, 4:by the projections 6, 6 and the next adjacent crank throws 14, 14: arestruck up by the projections 3, 3 into the cavities 5, 5, see Figs. IIand VI, the projections 3 being disposed at an angle for the preliminarybend so that the crank throws are properly deflected.

After the preliminary bending is completed, as seen in Figs. VIII andIX, the partially bent crank shaft is placed in the second recess withthe central throws 14, 14, 15, 15' in a horizontal plane where the endcrank throws 16, 16' are formed by the metal being forced into therecesses 7, 7 of the bottom die 2 by the projections 8, 8 on the upperdies and at the same time the dies coact to forge and forcethe shaftjournals down and the crank throws 14, 14 into the lateral recesses 9,9' throu h an angle of 30 degrees and the crank tirows 15, 15 into therecesses 10, 10. The drop hammer is operated sufficiently to completelyform the crank shaft with the usual projecting fin or flash. The fin orflash is then cut off and the crank shaft returned to the die and truedup.

A plan view of the completed crank shaft appears in Fig. X. The crankshaft with the fin cut ofi appears in perspective in Fig. XI, and therelation of the crank throws appears in the end elevation view -Fi XII.The form of the dies and their relation appear in Fig. IV the exactparting of the dies only appear in'connection with Fig. II or Fig. VIand the complete crank shaft appearing in Fig. X.

While this mvention is shown as applicable to a six throw crank shaft,it is very clear that it is adaptable to three or any multi le of threeand indeed can be made use 0 for any crank shaft having more than adouble throw. However, three or multiples of three lend themselves bestto this method because that only calls for a deflecting of certain ofthe crank throws through an angle of 30 degrees so that each lateralcrank throw stands at an angle of degrees from the perpendicular, whichis very readily accomplished in the drop hammer.

I illustrate an apparatus adapted to the forming of the intermediatecrank throws first and the end throws last, which has cerinsane? tainadvantages and which I desire to claim specifically. I, however, callattention to the fact that the dies can be so shaped and their recessesso located that the throws 1 and 6 may be deflected down, or possibly upin the second operation, or 2 and 5, or 3 and 4,v where a six throwcrank shaft is being forged.

I have shown the and which I desire to claim specifically. I also desireto claim the same broadly.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a means for formin crank shafts, the combination of a die withimpressions comprising recesses in which are projections for formingpreliminary vertical -bends to form intermediate crank throws,

the end projections of which are inclined and disposed at an angle tothe axial line thereof to give the initial lateral impulse to thecorresponding crank throw, a second impression for completing theoperation containing deep vertical recesses to form the end crankthrows, and lateral recesses to receive and deflect the intermediatecrank throws after the first bend, 'coacting for the purpose specified.

2. In a means for forming crank shafts, the combination of a die withimpressions comprising recesses in which are projections for formingpreliminary central vertical bends to form the throws, and a secondimpression for completing the operation containing dee vertical endrecesses to form the end tfirows, and lateral recesses to receive anddeflect the central crank throws after the first bend coacting for thepurpose specified.

3. In a means for forming shafts, the combination of a die withimpressions comprising recesses in which are projections for formingpreliminary vertical bends to form opposite and adjacent crank shaftthrows, a second impression for completing the operation containing deepvertical recesses to form additional crank shaft throws, and lateralrecesses to receive and deflect.v the first formed throws after thefirst bend, coacting for the purpose specified.

4. The method of forming a crank shaft consisting in bending the shaftpreliminarily in substantially a vertical plane to form the centralportion of the crank throws, and thereafter bending the additional endcrank throws at substantially a right angle to the plane of the firstformed throws and deflecting the first formed throws into oblique planesin'the same operation.

5. The method of forming a crank shaft consisting in bending the shaftpreliminarily insubstantially a vertical plane to form the central crankthrows, and thereform preferred by meintermediate crank means? afterforming additional crank throws in a plane at substantially ri ht anglesto the plane oi the first crank t rows and deflecting the first formedthrows into oblique planes.

6. The method of forming a six throw crank shaft consisting in areliminary bend of the central four throws in the same plane, two to oneside of the axial line and two to the opposite side, and thereafterbending the end crank throws in a plane at substantially right angles tothe first throws, and deflecting the said first throws to oblique planesat angles of 60 degrees to the first plane, as specified.

7. The method of forging crank shafts consisting in first bending theintermediate crank throws, and then bending and forming the end throwswhile-at the same time deflecting the intermediate throws to ob- 8. Themethod of forming crank shafts consisting in first bending in a verticalplane opposed central crank throws and then bending and formingadditional end crank throws in a plane at right angles to the plane ofthe first formed crank throws and deflecting the first formed crankthrows to oblique planes of the required angle, as specified.

In witness whereof, I have hereunto set my hand and seal in the presenceof two witnesses.

HARRY H. KEEPORTS. [12. s.]

Witnesses:

FRANK CUR'rIs Moran, STEPHEN J. PYLES.

